fix typo in variable name in Fstab.insert

Stefan Grönke + Igor Galić · gronke · commit 91f1bed6d81e · 2019-02-07T14:39:46.000Z
diff --git a/libioc/Config/Jail/File/Fstab.py b/libioc/Config/Jail/File/Fstab.py
@@ -642,7 +642,7 @@ def insert(
             # find FstabAutoPlaceholderLine instead
             line = list(filter(
                 lambda x: isinstance(x, FstabAutoPlaceholderLine),
-                self._line
+                self._lines
             ))[0]
             real_index = self._lines.index(line)
         else:
